Maximum fuel efficiency for 2005 Tundra

I met a Tundra owner on the road who was using an iPhone and an obd 2 reader (with Bluetooth) to run his vehicle at 80% power to obtain maxim fuel efficiency. Anyone have some guidance on what reader would work for this and what parameters I would need looking for to run at maximum fuel efficiency?
I have a 2005 Tundra
Thanks

 

I turn off OD below 55mph. Learned that trick watching the mpg gauge on my moms ‘04 sequoia. But the vvti might change that. Since i’m pretty rural, and have a further distance between stoplights, i accelerate quicker, so i spend more time coasting. And i judge the traffic ahead of me to minimize how much i use my brakes. Best tank was 21.6.

read up on hypermiling, but my non-vvti doesnt like to be driven like a diesel, the engine really prefers to be above 2krpm on hills. And dont use cruise control.

 

Cut all the weight you can. Small, light street tires. Drive like your granny.

Not much else you can do with our trucks.

 

I never got better than 16 mpg with my 1st gen Tundra with the 4.7, 4x4.

 

Here is averages for 05 MPG. Trucks are not built for MPG. No lift, keep SL load street tires on it and drive like a granny. If you average 15 or above consider that good/normal.

https://www.fuelly.com/car/toyota/tundra/2005